HEC: Potential Habitable Worlds Ranked by Similarity to Earth

THIS LIST IS OUTDATED, CURRENT LIST IS AVAILABLE HERE (NOT IN GRAPHICAL FORM).

This list shows 16 potential habitable worlds, including confirmed and unconfirmed exoplanets, ranked by similarity with Earth using the Earth Similarity Index (ESI). The ESI is an overall measure of Earth-likeness for exoplanets based on basic planetary properties. Exoplanets need to have similar radius, mass, and surface temperature as Earth to be ranked high on the scale. Check the METHODS for an explanation of the metrics and classifications systems used here. Latest results are available in the DATA section of the Habitable Exoplanets Catalog.

NOTE: Those names starting with Kepler Object of Interest (KOI) link to the NASA Kepler Mission original data. However, we used updated stellar values from Muirhead et al. (2011) that modified the stellar properties and reduced the estimated radius in many cases. Mass or radius was estimated when not available with a mass-radius relationship assuming a terrestrial planet composition. The surface temperature calculation assumed a scaled greenhouse effect similar to Earth. More details about this data is available here.